Self-contained ecological watering system

ABSTRACT

Self-contained ecological watering system, protected against obturations, and capable of irrigating at low cost uniformly and regularly a variety of cultivated areas; the system operates automatically a series of fertirrigation cycles requiring minimum actuation power and reduced water flow rate. The system permits implementation of various configuration including a plurality of local subsystems ( 1 ) which are controllable locally or from a remote station ( 6 ); each subsystem comprises a container ( 2 ) capable of accumulating the volume of liquid to be discharged per cycle, a watering assembly ( 3 ) capable of regulating the watering volume and discharging it upon receiving a low power signal; a low consumption electronic control unit ( 4 ) capable of determining the frequency and the appropriate time to send said signal; and a low restriction distribution network ( 5 ) capable of transporting the water to irrigate the locations in need.

FIELD OF THE INVENTION

The present Invention belongs to the technical area corresponding tosystems for located irrigation, also called microirrigation field.

In particular, it proposes itself as new alternative of adaptative andsustainable technology, against other well-known microirrigationsystems, characterized by the possibility of operating automaticallywatering, according to the necessities of the ambient, the man and thecultivations, with accent in natural resources saving and energyautonomy.

INTRODUCTION

The necessity of new and better solutions to the feeding of thevegetable species cultivated in the planet, is affected nowadays byopposed tendencies.

On one hand, the growing alimentary demand of a world population thathas not stopped to expand, has taken to use new technologies in order toforcing the productive yield of lands on the edge of exhaustion, as wellas to extend the frontiers from the agriculture to areas beforerejected.

On the other hand, the disposition of elementary natural resources assoil, water and air was narrowed, as a consequence not only of thedemographic growth but also due to environmental contamination andnegligent uses, increased by degrading effects in the climate.

When being definitively lost or deteriorated an important part of thenatural wealth, is no longer so easy to use indiscriminate orunilaterally the essential resources, not even with the intention ofsatisfying those requirements.

Therefore, it is imposed to qualify well-known or new solutions,strictly based on a conception of the planet as ecosystem.

If being affirmed the present tendency to reduce agrochemicals usetoward a more organic agriculture, it will surely imply a more rationalemployment of natural factors, to service the global necessities of theecosystem.

So, while water able for feeding human or vegetable is becoming a scarceresource, still in traditionally favored regions, it arises as ahigh-priority necessity to solve the problem of watering with rigorousefficiency approaches for savings on the element and its use.

A second requirement of current validity is to include the so called“fertigation” that takes advantage of the hydraulic road to incorporatefertilizers, medications and other chemicals in the most economic form.This acquires special importance in the exploitation of over used lands.

A third important necessity refers to the economic use of sandy or loamycomposition soils, where the nutrients shortage is intrinsic.

A fourth emergent phenomenon, related with those formerly exposed,consists in the saline problem, involving three aspects: to recoversoils very much exploited from deep salinization; to incorporate ascrops lands, areas traditionally rejected by their saline content, andfinally the feasibility of watering with brackish water, when it is theonly one locally available.

A fifth necessity arises from the increasing tendency to automatecertain agricultural systematic operations with the intention ofimproving and regulating productive results, so much when thecultivations are carried out covered in modern greenhouses, as when thegoal is to diminish climatic risks, to reduce heavy human tasks and toimprove results cultivations yields. Said “fertigation” techniques areparticularly able to be automated with advantage, but until the presentit has implied high costs, maintenance inconveniences, bigger energyconsumption and cultural difficulties for their adoption.

A sixth necessity refers to the emergent market of non-assisted wateringof home gardens or alike, more and more extended in the breast of bigcities possibly as a compensatory tendency to their characteristiccontamination and excessive population living there.

In the current state of the technique—that will be referred detailedlyin the following paragraph—the mentioned necessities are far from beingintegrally satisfied, still considering the last and well-known advancesin located watering, as for example drip and trickle irrigation.

It is in said context that the present Invention appairs, providing aSelf-sustained Ecological Irrigation System able to assure anappropriate feeding to the cultivations, based on a significantresources economy and also giving answer to the other outlinedrequirements.

To achieve those results, it combines traditional technical resources,as for example gravity liquid conduction and distribution with moremodern technical resources as for example employment of distributionnetworks implemented with low cost and simple manipulation plastic pipe;with further more recent technology resources as for example theprogrammable intelligent command module acting automatically inclose-loop mode by means of sensors; and finally with special innovativeresources, as the incorporation of an hydraulic discharge valve able ofworking with big flows using very tiny energy.

Summarily, the Invention in a basic configuration comprises at least aself-sustained ecological irrigation subsystem feeding a limitedcultivation sector having homogeneous requirements, assisting itautomatically during an indefinite period that could embrace thecomplete evolutionary cycle of the referenced vegetable species.

The Invention operates periodically along a cycle—generally dailypreferable—comprising a first preparation sub-cycle embracing most oftime of the total period, followed by a second discharge sub-cycle withrelatively shorter duration, finally restarting the cycle from itsbeginning.

Said preparation sub-cycle is employed to accumulate in a deposit thetotal volume of water to be discharged per cycle, through a minimum flowrate. After reaching the preset maximum level, the System rests in await state. Additionally, a mechanism of triggered discharge isprepared, accumulating potential energy in the form of pressurized air,into a special configuration of hydroneumatic siphon device.

This preparation sub-cycle is also employed by the Invention tointegrate in an integrator mean, incoming electric power for examplegenerated by a photovoltaic convertor, so dimensioned to guarantee—withthe aid of energy storage means—the uninterrupted operation in the mostunfavorable conditions.

A command circuit determines from preset conditions the adequate momentto the discharge and executes it by sending a reduced energy impulsiveelectric signal to a pneumatic trigger device that evacuates saidpressurized air, causing a high flow discharge until emptying thedeposit in few minutes. Doing so, the beginning of a new cycle isimmediately enabled.

The discharge is driven through a low restriction distribution network,in which the major hydraulic loss is spread between the located emissionholes whose diameter is about some millimeters. It determines arelatively uniform space distribution, without the intrinsic obturationdangers of other narrow passage restrictors.

STATE OF THE ART

If one observe the fundamental tendency with which the watering methodshad historically evolved, as human inventive exercise to increase theproduction of foods palliating climate risks or the characteristics ofthe cultivated land, a progressive tendency can be identified, toward amore and more precise application—in spatial, rythm and volumeterms—with the consequent water savings.

On the other hand, this techniques have evolved imitating the twonatural phenomenons that provide useful irrigation water: rivers andrains.

First of all, antique systems as dams, aqueducts, channels and furrowswere perfected, integrating the so called surface watering in referenceto the application form; or by gravity referring to the type of energythat impels the liquid toward its destination.

Then, the mechanical advances that characterized the first half of thepresent century, allowed the directed emulation of precipitations bymeans of fixed powered sprayers. These facilities, where the water ispiped and pressure impelled, allowed to increase watering efficiencyessentially by reduction of the distribution losses. Among the lastachievements of this technical group the one denominated central pivotwatering stands out, being able to feed circular areas with radius ofsome hundreds meters by rotating a motorized line of sprayers, or theeven more complex front advance system comprising powerful self-mobilepumps.

The mentioned systems had been employed successfully when the waterabundance or the public support of the financial efforts to build thehydraulic base installations, didn't impose strict limits to theirprivate feasibility. In what relates with spraying systems, thesignificant consumption of energy in terms of transport and drive couldbe financed especially in advanced or developed countries, as directconsequence of fuel availability and/or rural electrification.

However, a new generation of watering systems was originated by severerestrictive conditions, together to the necessity of a bigger control onthe evolution of the crops: the High Frequency Located Watering(microirrigation) systems.

Comprising basically techniques like drip irrigation, micro-aspersionand porous transpiration pipes; and directed originally to achieve amore precise application of the water, these equipments were onlypossible based on the last plastic industry advances that allowed tomanufacture in great volume series, engineered pieces of intricatedesign made with new, high environmental resistance materials, atcomparatively low cost.

These methods carry the water practically to the plant root, by means ofsophisticated miniaturized emitters, fed by a net of small sectionconduits and employing relatively low pressure. They implied not onlyquantitative improvements in watering efficiency—particularly in case ofpermanent roots species—, but rather produced a true agriculturerevolution¹, founding new cultivation methods and expanding the arableareas over former rejected areas.

Surely, the most influential and more extended system has been the firstone. It is convenient in order to detail art previous to the presentInvention, to closely examine the drip method.

It is known the fact that the first invention patents referred to DripIrrigation industrially realized, have been originated in the State ofIsrael, where the vital necessity to transform the desert into croparea, could be conjugated with a high technological level based on othernecessities.

At the moment when the Drip technique arose, the agronomic aspects ofwatering had already been object of profuse investigation for a lot ofdifferent species. The concepts of irrigation efficiency could berefined, discriminating its various aspects.

Been focused from the scope of hydraulic distribution, the use of waterfor the cultivation, or accenting in the energy cost of the feeding; itwas already possible to quantify projects with sufficiently predictableresults. It was developed, then, a watering method that tried tostrictly adapt—in physiologic and economic sense—to that required by thecultivation in a scenario characterized by the shortage of water.

The heart of the method of the Drip Irrigation is the emitter ordripper, miniature piece of hydraulic engineering generally plasticinjected, able to be massive manufactured at relatively low cost.

Functionally, the typical evolved dripper is a pressure and flow reducerdevice achieving very high hydraulic losses, with a fixed a linealresponse to input pressure of the exponential type using generallyfractional exponents, specified by a nominal quantity of emitted flow,commonly of about 1 and 10 liter/hour for a standard input range offeeding pressures between 5 and 50 meters of water column height.

The main contribution of the Drip method is apparently simple: importantwater savings because of spatially uniform located distribution of theinput flow to the cultivated area; with low investment and energyconsumption as compared with traditional methods.

Gravitating precisely this factors of efficiency in the economicfeasibility of certain cultivations or the use of wide areas, theemployment of the referred method became a decissive key factor.

The immediate effect of dripping or other located waterings over acultivation is generally a better production, with a savings of aboutthe 50% in the used water. Their growing expansion is due to thisadvantage that has demarcated a before and a later especially in whatrefers to intensive agriculture, powerfully influencing the permanentroot cultivations but also those of shorter cycle as vegetables andflowers.

A secondary advantage of utmost importance became evident a little timeafter the appearing of these methods, related with the salinizationproblem.

After early experimental investigations², it was established that withcertain flow levels and application frequencies, Dripping is able toproduce a local salt wash out from the soil volume near to the root zoneof plants, restoring gradually the original productivity in a quickerand more efficient way that with the “flood” practices former used.

In 1977 Bresler (USA)³ described the method as creating a micro-zonenear the emitting point called “humid bulb”, its form and dimensionscorresponding to the watering application regime an soil properties.

The fact that the plant adjusts its root configuration radicular toadapt inwardly to this humid bulb, gives place to an agriculture inwhich it is possible to improve a harmfully mineralized soil at lowcost, at least in the small enclosure where the plant is inserted, andthat this improvement is controllable up to will in agreement with thenecessities of the cultivation.

It should be emphasized here that the mentioned work, comparingdifferent soil structures and flows of the located watering, establishedthat the most convenient form of said bulb was obtained applyingrelatively higher flow regimes for equal total volume amounts applied.Presently, this fact has been broadly proven and spread by thespecialized literature.⁴

Indeed; the consequence of applying a higher instantaneous flow (as theprovided by the present Invention) is a humid bulb of smaller verticaldevelopment and bigger horizontal expansion that the one generated bythe Drip one, favoring the radial root development influencing a directincrease over the yield.

Later investigations, relating the formation of the humid bulb with thedistribution in the saline concentration when being used the Dripwatering method, demonstrated that the high frequency locatedapplication displaces the salts toward an outlying capsule that wrapsaround the bulb, but leaving enough space to provide a satisfactory rootdevelopment.⁵

Again, it was revealed that this phenomenon results more effective withhigher instantaneous flow applications.

In summary, the importance of the Drip watering method exceeds goes faraway in the best water use, allowing the revaluation and use of the soilresource.

In large countries as the República Argentina that—in relative terms—isone of the world's lesser watered, only embracing 3% of the arablearea⁶; presenting a soil salinization problem that reaches danger levelsand significant extensions, the necessity of adopting a solution withthese characteristics becomes more than evident.

However, and nevertheless the significant advantages previouslyexplained, the practical implementation of the Drip watering techniquehas been revealing inconveniences of not so little importance, ending upto neutralize those advantages in certain situations, but also limitingagainst all that foreseen the tendency of its growing adoption.

The inconvenient is so simple but affects the heart of the method: thedrip emitters are easily plugged.

The sources of this deletereous obturation phenomenon had been describedas of inorganic origin (silts, salt precipitation) or organic one(formation of bacterias and/or microscopic algae colonies in low flowsectors of the net), this last phenomenon increased by the employment ofliquid fertilizers in fertigation practices. For example, the main causeof massive obturations to microirrigation systems in Israel had beenattributed to the growth of protozoaria colonies like EpystilysBalanarum or sulfur bacterias like Beggstoa Alba.⁷

With more reason, in less technological or cultural developedenvironments or with infrastructure carencies, difficulties have takenplace with the Drip method. Such the case, for example, of thatinvestigated among farmers of the state of Maharashtra, India.⁸

After the accumulated experience of numerous anomalous operatinginstallations was of public domain, engineering correctives efforts wereapplied, in the intent of preserving the initial advantages of thetechnique.

Necessarily, the solution should be found as improvements in the dropperdesign, in order to conserve the technical and economic coherence of themethod.

This way, the miniature labyrinths responsible for the functionality ofemitters were redesigned, trying to palliate the inconvenience.

New concepts were developed, looking for achieving flow restrictionbased on hydraulic resistance self-induced by turbulent circulation,instead of the former undersizeing of emitter passages.

Special geometry entrance cavities were adopted, to contain theparticles by way of low restriction hydrodynamic filtering.

However, the opposing solutions were only partial ones. The accumulationof particles was proven irreversible, and obtrutions only matter oftime.

The problem was that the adding of vortex generators doesn't diminish,but rather gives place to a progressive growth of the deleteriousdeposits, making that the main property of the emitter i.e. its nominalemission flow, be changing along with the use as an uncertain time law.Finally, the phenomenon ends deteriorating the uniformity of spacedistribution, in fact the main advantage of the Method.

Indeed; the option among laminar flow restrictors that are aleatoryplugged and vortex designs changing progressively with time couldn't besatisfactory.

Also the response uncertainty is increased by means of the initialemitter response as a normal statistical effect of its manufacturing.ISO standards, for example, categorizes emitters into at least twoprecision classes, according to the tolerance group to they belong,imposing a clear labelling of the product and obvious costdifferentials.⁹

Starting from these difficulties, answers begun that go beyond theeffort of improvement the system without deeper changes.

Emitters comprising detachable parts for their cleaning are proposed,but asking for specialized manpower and stops for maintenance. They aremarketed, even, manually trimmable drippers.

Self-cleaning designs were registered, allowing inverse flow to removeplugging. Their use requires, however, additional devices like specialvalves or generators of that flow.

As the mentioned efforts were proven insufficient, it should berecognized the necessity of including in the facilities of Dripirrigation, expensive centralized equipment as precision high flowfiltering stations, pressure regulators and flow integrators.

This instrumental, as for example the Woltman¹⁰ turbine type, has errorsof more than 2% and high load loss but becomes obligatory in drippingdue to the impossibility of knowing with certainty the volume of waterprovided to the plantation as becomes impredecible the relationshipbetween flow and pressure in the distribution network.

The necessity to justify the use of these expensive facilities, forcesto employ a centralized configuration for the watering distributionnetwork, with bigger costs dedicated to long conduits of importantsection, electrovalves, etc. Which in turn requires an appreciableenergy consumption, harmful among other reasons because it bears astrong dependence of the cultivations to the electric lines or the fuelprovision sources.

To this height of the present discussion, it can be already appreciatedthe partial limitations that affect the expansion of the Drip method ofwatering.

In the practice and because of plugging, the system is strongly affectedby heterogeneous distributions and impredictable watering reductions,unless incorporating complex filtrate equipment, regulation of pressurespread along the net, flow measurement and alarm automatisms.

The theoretical feasibility of Dripping for fertigation and/or to usehigh sine content waters, dissapears when these practices increase thetendency to the pluging of emitters.

This way, the Drip method reveals itself as fragility affected, unlessit is provided a sophisticated, expensive installation and linked to theelectric power net or some other energy source.

So, become excluded from its application the lower developed regions ofthe world, in which the rural exploitation lacks of if structure and thesocio-economic and cultural environment that appears as a must for thismethod's functionality. Significantly, those lands where efficientwatering is more necessary.

Among the alternatives proposed against the Dripping's inherentdifficulties, the intermittent or pulsating method could be remarked. Agood example is Spencer's invention¹¹, that points in solving theproblems caused by extremely restricted emitters.

To achieve this objective without losing the liquid savings achieved bythe previous art, he appeals to obtain the reduced flow by acting on theso called integral cycle relationship, providing irrigation cycles eachone comprising brief, high flow pulses, followed by relatively longernon watering intervals.

Using high line pressures, high-speed electrovalves and retention onesin conduits and emission openings, referenced invention is indeed ableto attain reduced average flow—adjustable by modifying timerelationships—but pulsing high instantaneous flow through biggerorifices.

The obturation risk is this way minimized, at the cost of moremechanization, complexity, mechanical wear out and an increaseddependence respect the energy net.

A modern technology corrective approach is offered by Desrues et al¹²,employing massive use of sensor local feedback and central computerizedprocessing into closed-loop mode to achieve real time adaptation to thecurrent conditions of the cultivation, compensating non uniformities inthe watering dilution by means of multiple remote control of adressableelectrovalves. Again a technically effective solution is from anotherpoint of view, an expensive, complex and of high energy consumption one.

Viewing the outlined scenario, it results in synthesis that the HighFrequency Located Watering as a concept that prioritizes the uniformpunctual distribution has been agronomic and economically better inreference to the conventional gravity or surface methods and powerfulaspersion; but the industry has not provided yet general solutionscomprising the variety of situations in which the agriculture works.

In highly agricultural extense regions within the so-called Third World,the rural lack of development turns impracticable the employment ofelectro-mechanic-intensive technologies.

Further more; due to the crisis of non renewable energy experienced bythe planet in the last decades, even the agricultural sector of therelatively high developed countries becomes increasingly interested intechnological improvements based on simple operation principles, lowcost and extended useful life, reducing pollutants and enabling thehigher attainable energy autonomy. Nevertheless, until the presentInvention it didn't appeared a sufficiently integral and reliablesolution for the problem of watering operating exclusively by means ofsolar energy.¹³

The ecological consistency enunciated at the beginning, remainstherefore unfulfilled for the previous art of watering; situation thatis in fact what comes to satisfy the present Invention, together withother objectives that are exposed in the following paragraph.

FINALITIES OF THE INVENTION

In the following lines, the purposes that the Invention executes areenumerated, grouped by aspect of interest

The detailed description along with the enclosed drawings, illustratethe structural means and operation principles that the Invention employsto satisfy said requirements.

AGRONOMY

Flexible agronomic effectiveness for a wide spectrum of locatedcultivations.

Adaptability to different extensions and configurations of the irrigatedarea.

Fertigation feasibility.

RESOURCE: WATER

Maximum distribution and use efficiency of the resource.

Control and regulation of the volume of water given to the cultivation.

Predictable operation, even with irregular water input flow.

Capacity of automatic compensation to the cultivation for lapses ofabsolute drought.

Use of high saline content waters.

RESOURCE: SOIL

Use of, sandy loamy or low nutrients soils.

Use and/or recovery of salinized soils.

OPERATION—ECONOMY

Simple and intuitive operation.

Extended useful life with null or scarce maintenance.

Low risk of obturations without necessity of special filtering neitherpressurization.

Reduced energy requirement.

Autonomy regarding the energy provision.

Configurations with different degrees of automation y/o remote control.

Selectable automatic or manual operation modes.

Automatic watering to open field or covered crops.

Domestic version: non assisted watering of homelike garden or smallvegetable crops.

Reduced cost of the centralized irrigation equipment and thedistribution network.

Controller optionally compatible with an already existentmicroirrigation net.

SUMMARY OF THE INVENTION

The enunciated finalities are exactly satisfied by the presentSelf-sustained Ecological Irrigation System that in a basicconfiguration with only a single local subsystem, comprises four mainparts:

a container with enough capacity to contain the total volume of water todischarge in each cycle;

a positionable irrigation actuator device, able to first adjustablycontrol the filling and then the pulsed discharge of the liquidaccumulated in the container with a very low energy expense, thanks to anovel elechydro-pneumatic mechanism;

a command module, generally of electronic nature with reduced electricconsumption, able to trigger the operation of said actuator; and finally

a distribution watering net able to distribute the total volumedischarged with generally high and uniform flow, toward a plurality oflocalizations inside the cultivation area.

Summarily, the operation of the Invention comprises a first preparationphase that generally includes a stable wait state; followed by a seconddischarge or properly watering phase, generally taken place by thewatering actuator when being triggered from the command module.

The liquid spreads quickly through the distribution network producinglocal watering by way of multiple emission of similar end flow; this endflow being only determined—for a given input flow—by the dimensionrelationship between emitter's and conduit's passages.

Because of said pulsed discharge principle triggered by a very lowinitiation energy, the operation of the system is generally independentof the electricity lines, operating dependably for example based onsolar energy, being able however to discharge large volumes in a shorttime.

Lastly, it is this structure and operative principle what confers to thepresent Invention its application versatility, and the ample spectrum ofconfigurations, control complexities and design variations with whichcan be industrially produced.

DESCRIPTION OF THE DRAWINGS

In order to better illustrate the structure and operation of theInvention, the following drawings are enclosed within the presentmemory:

FIG. 1 functional outline of a preferred implementation of theInvention, according to a general configuration comprising a pluralityof local subsystems;

FIG. 2 functional outline of a preferred implementation of one of thelocal subsystems of the Invention, for a complete application;

FIG. 3 schematic illustation of a preferred implementation of thedischarge actuator subset;

FIG. 4 schematic view of a preferred implementation of the triggeringdevice; and

FIG. 5 functional block outline of a preferred implementation of thecommand module according to a general configuration.

STRUCTURAL DESCRIPTION OF THE INVENTION

The present Invention possesses a basic constituent structure thatremains the same through the different realizations with which it can beembodied; or the variety of concrete situations to which is able toadapt its configuration and benefits.

Although the Invention as a watering system represents a novelty inreference to what is already known by means of its new characteristics,it includes an essential novel nucleus that makes it possible and whichconstitutes the true source of originality for the hole apparatus.

This novel nucleus resides in the configuration and operative form ofthe denominated local watering subsystem; and precisely in the so-calledwatering actuator.

The detailed definition of this unique, main object of the Invention andits corresponding hierarchical novelty structure, is the object of aspecial section of the present memory.

In order to better distinguish this basic structure, the Invention isdescribed from a general to a particular scope, describing first thesystem, then the subsystems and finally the concrete subsets or devicesincluding some preferred constructive and/or operative options.

This way, a general implementation of the Invention as illustrated inFIG. 1 comprises a system of programmable watering applied to anagricultural establishment of considerable extension with diversity ofproductive parcels, operating a plurality of decentralized units towater by demand adapting to each one of the particular situations.

As it is observed, this implementation comprises a plurality of localsubsystems (1), each one of them watering an homogeneous characteristicscultivated sector, said local subsystems being water fed from the nearersource; and operating autonomously based on—for example—solar energy.

Said local subsystems (1) possess a common structure, comprising a watercontainer (2), a positionable watering actuator assembly (3), a wateringcommand assembly (4) and a watering distribution network (5).

On the other hand, a central control station (6) comprising a remotecommands codifier circuit (7), a commands multiplexer circuit (8)pointing to each one of the local subsystems (1) and a remote controltransmitter circuit (9) connected with said subsystems by means of anumber of communication channels (10), is able to set or remotely modifycertain operative parameters of the subsystems, according to thatestablished by a human operator.

Said commands could be, for example: to enable or temporarily suspendthe automatic watering; to modify the duration of cycles; to makeasynchronously an additional watering cycle; to enable an automaticcompensation for drought; or to enable the automatic incorporation offertilizers, among others.

FIG. 2 illustrates with more detail the preferred constitution of one ofthe mentioned local subsystems. It can be observed that comprises awatering liquid deposit or container (2) with enough capacity to containthe total volume of water to be discharged into a cycle, including avertical ruler (11) graduated in capacity percentages or directly inunits of volume, in concordance with the corresponding inside height ofthe liquid.

Said container (2), elevated a few meters in reference to the landlevel, possesses a flexible hydraulic connection (12) emergent from itsbottom, able to communicate optionally with the positionable wateringactuator assembly (3) through the capacity expansion shuttable connector(13), in order to extend the watering volume capacity of the subsystemuntil satisfying what required by the assisted cultivation.

The positionable watering actuator assembly (3), comprises a bodyconsistent in a recipient of limited capacity (14), tightly closed bythe top cover (15).

Said positionable watering actuator assembly (3) also comprises afilling controller subset (16), integrated by a controllable input flowregulator device (17) of the flow of liquid entering to the subsystemfrom an external source; a controlled level regulator (18) including ashut-off valve (19) acted by a controllable floating device (20) able tolimit the filling level of the recipient (14) same as the liquid levelinside the container (2), in the event of being both connected by meansof the flexible hydraulic connection (12)—to a regulated filling levelvalue (21). In coincidence with this level (21), a pointing device (22)fixed outwardly to the body (14), allows to establish the filling setpoint level, positioning vertically the positionable watering actuatorassembly (3) according to that indicated by the pointing device (22) onthe ruler (11). The positioning can be carried out manually or inautomatic form by means of the vertical displacement servomechanism(23), acting on an appropriate point of the body (14).

Also included inside said body is the discharge actuator subset (24),comprising the hydro-pneumatic siphon device (25) having the air reliefmg discharge control conduit (26); and the discharge conduit (27).

Said hydro-pneumatic siphon device (25) is shown with more detail inFIG. 3, being seen that it comprises three hydraulically sequentialparts, that is: an ascending or input sector including the supplementaryinput threshold device (28); a descending or discharge sector includingthe supplementary discharge threshold device (29) and an intermediate orelbow sector (30); comprising also a fourth pneumatic part connected inderivation with the described hydraulic circuit, consisting in apressurized air camera (31), connected with the air relief dischargecontrol conduit (26); the mentioned device (29) ending in the dischargeconduit (27) mentioned above.

In the coaxial implementation of FIG. 3 configured by means of basicone-end opened recipient forms that can be told like glasses put in upor inverted position, it is observed that the supplementary inputthreshold device (28) consists on an external first inverted glass (32)whose mouth ends near the bottom of the recipient (14), including in itstop half zone a second up glass (33), which in turn contains the elbowdevice (30) configured by a third inverted glass (34) and inside it, theexit tube (35) that extends vertically down, being inserted in thesupplementary discharge threshold device (29)

Given the importance of its behavior in the particular way with whichthe Invention operates, it should be remarked here that the dischargetransition camera comprised in the elbow device (30), consistent in thehydraulic passage among the bottom of the inverted glass (34) and thetop end of the exit tube (35), possesses a hydrodynamic design setting acontinuous transition between sections, in order to obtain a precisedefinition of what will be called the spontaneous discharge threshold,on the base of assuring a laminar flow circulation of the liquid throughsaid elbow in the precise moment of transition to discharge. Said aspectcan be clearly observed in the referenced drawing.

The higher zone of said first inverted glass (32) presents a pressurizedair camera (31), being able its air to be evacuated through thedischarge control conduit (26).

The exit tube (35) above mentioned, extends until almost touching thebottom of the up glass (36), contained in turn by the end glass (37),which communicates through its bottom end with the discharge conduit(27) already noted.

The described structure provides a plurality of pressure levelsequivalent to potential energy thresholds that can be quantified forexample in terms of units of water column height, those pressure levelsbeing determined solely by certain dimensional relationships in theInvention's structure, being:

the supplementary input threshold UT (38), equal to the difference ofheight among the open end of the inverted glass (34) and the top end ofthe exit tube (35);

the supplementary discharge threshold UD (39), equal to the differenceof height among the open end of the normal positioned glass (36) and thebottom end of said exit tube (35);

the transition discharge threshold of the elbow, here denominated levelor threshold to basic spontaneous discharge UDB (40), generally equal tothe absolute height of the top end of the exit tube (35); and

the global spontaneous discharge threshold UDG (41), combining theperformance of the previously mentioned devices and being equivalent toan absolute height equal to said basic spontaneous discharge thresholdUDB (40), added with the other already defined values of supplementarythresholds:

UDG=UDB+(UT+UD) [units of H2O column height]

The controllable floating device (20) former mentioned, includes asection of controlled floating camera comprising at least a cavity (42),bottom opened and top closed, able to trap pressurized air as the liquidlevel in the recipient (14) ascends, so contributing to the push forceacting the limitation of filling by means of the shut-off valve (19);the superior part of this cavity (42) being communicated by means of theflexible filling level control conduit (43) to allow the evacuation ofsaid pressurized air, said conduit (43) emerging through the top cover(15) to communicate with a trigger device in order to produce the reliefof pressurized air.

Tightly fixed in said top cover (15), there are control means,comprising at least a trigger discharge device (44).

For more descriptive detail, the preferred implementation illustrated inFIG. 4 may be observed. It can be seen that said trigger dischargedevice (44) comprises a pneumatic bistable electrovalve (45) providingretention in both opened or closed states, plus optionally disabledone-way or retention characteristic, by means of the pneumatic retentionvalve (46). Said electrovalve (45) includes a generally tubular hermeticroom (47) inside which a generally cylindrical mobile nucleus (48) builtwith magnetic material, slips with low friction; the bottom end of thisnucleus being covered with a thin resilient sealing layer (49).

In its bottom zone, the hermetic room (47) presents an enlargement thatgives place to the action camera (50).

The input conduit (51), communicates the inside space of the mentionedhermetic room (47) with at least one of the controlled actuators (18) or(24) through the corresponding control conduits for relief ofpressurized air, that is: the discharge control conduit (26); and/or thefilling level control conduit (43). The top end of said input conduit(51) is sharpened, allowing a perfect sealing against the resilientsealing layer (49), thanks to the weight action of the mentioned mobilenucleus (48).

An exit air conduit (52) communicates the inside space of the tubularhermetic room (47) with the pneumatic retention valve (46), easilydisabled by the user to configure the operative options.

Once opened, said valve (46) alleviates pneumatic pressure toward theatmosphere.

The activation of the pneumatic bistable electrovalve (45) is producedby circulating of a brief electric current pulse in a certain “on”direction, by the solenoid (53) that surrounds closely the externalsurface of the hermetic tubular room (47).

Externally fixed in the top end of said room (47), a magnetic retentionmean (54) as for example a permanent magnet, is able to overcome theweight force of the mobile nucleus (48), if it has risen enough to reachthe magnet's influence field. By means of such disposition, thepneumatic bistable electrovalve (45) can be indefinitely retained in anopen state, without any current circulation through the solenoid (53).

The electro-valve dimensioning also must allow that, being the solenoidexcited by a brief current pulse of inverse or “off” polarity theretention be nulled, falling down the nucleus by effect of its weightuntil reaching the closing position, state in which it can of courseremain indefinitely without any further energy consumption

Also tightly fixed in said top cover, additional actuating meanscomprise an unidirectional expansion valve (55) optionally disabled; thevacuum conduit (56) communicant with a vacuum actuated liquidchemigation doser (57); and the irrigation water input conduit (58)connected with the controllable input flow regulator device (17) alreadymentioned.

Additionally installed in said cover (15), an operative state sensor(59) of non-contact type as for example a Hall effect device, is able todetect the stand by or filled operative states, proximity sensing a meanof magnetic marker (60) mounted on the controllable floating device (20)already mentioned, to provide feedback to the command circuits.

The determination and automatic execution of the irrigation processcyclically realized by the Invention, constitutes the responsibility ofthe watering command assembly (4) previously mentioned, illustrated inFIG. 5.

As observed, the watering command assembly (4) comprises an electroniclow power command module (70) with very low electric consumption, ableto process information to determine the characteristics of the wateringcycle and opportunely emit excitatory low energy electric signals inorder to implement its execution; said electronic low power commandmodule (70) comprisinging a water-tight sealed cabinet (71), containingat least a first circuit for attending local controls (72); a secondcircuit (73) decoder of remote control signals; a third circuit (74)conditioner of sensor originated signals and a fourth real time clockcircuit (75) fed with an independent power source (76); said fourcircuits being connected to provide information to a fifth circuit (77)of logical processor, this circuit of logical processor beingbidirectionally connected with a sixth circuit (78) of permanent memorycontaining the operative program; and with a seventh circuit (79) ofrewritable memory comprising an eighth circuit (80) of non-volatileremovable memory chip; the logical processor circuit (77) abovementioned, being connected with a ninth interface output circuit (81)providing excitation signals to the actuating devices already mentioned.

The above mentioned circuits are implemented with a minimum energyconsumption electronic technology type as for example CMOS, beingenergized by a tenth power circuit (82), connected to receive electricpower from an external autonomous low maintenance source, as for examplea photovoltaic converter (97), designed with enough capacity to assurethe autonomous operation of the mentioned watering command assembly inthe most unfavorable solar condition case; this feeding circuit beingalso connected to an electric accumulator mean (83), designed toguarantee an autonomous operation of said watering command assembly,during an adequate period of time in the event of temporary reduction ofenergy provision by the above mentioned low maintenance source.

The cabinet (71) formerly mentioned presents fixed connection means toreceive signal inputs coming from external elements, i.e.: connector(84) with the output signal of a remote control receiver circuit (85);connector (86) with the opertive state sensor (59) included in thewatering actuator assembly (3); connector (87) with a plurality ofsensors (88) to receive feedback information from the cultivation andits environment; and connector (89) with external reprogramming meansfor example a portable computer (90).

Said cabinet (71) also presents emerging connection means to directoutput signals to external actuators, i.e.: connector (91) with theinput flow regulator (117); connectors (92) and (93) with triggerdischarge devices (44) acting over the filling controller subset (16)and the discharge actuator subset (24), respectively; connector (94)with the vertical displacement servomechanism (23) in the positionablewatering actuator assembly (3); and connector (95) with the vacuumactivated chemigation doser (57).

Finally, a connector (96) allows the electric power etrance fro m theexterna l means of photovoltaic converter (97).

The watering distribution network (5) former mentioned, is connect ed toreceive liquid from the discharge conduit (27) belonging to thepositionable watering actuator assembly (3), present ing a dischargeflow regulating valve (100), continued by at least a primary branch(101) and a plurality of secondary branches (102) derived from the ffstone, generally having ample section passages and low ruggedness in itsinside walls; presenting said secondary branches (102) a plurality ofemitter holes (103), each one of them generally having fixedly inserteda small longitude emitter conduit (104), being the inside passagesection of said holes and conduit, significantly smaller than the insidesection of the secondary branches (102) above mentioned, but yet withenough dimension—generally with diameter of a few millimeters—to allowthe quick evacuation toward the plants of the local portion of thewatering liquid discharged.

DESCRIPTION OF THE OPERATION

The operation of the described structure is next exposed, focusing inthe performance of a local subsystem (1).

Being established the necessity by the controlled level regulator (18),the water enters with a flow value determined by the input flowregulator (17), to the recipient (14) of the watering command assembly(4). Being connected the flexible hydraulic connection (12) to use theoption of capacity extension by means of an external auxiliary tank, theliquid fills progressively in the deposit (2), serving the recipient(14) as a mirror of the level reached in that deposit

The watering a ctuator assembly (3) is vertically positioned with theaid of the pointing device (22) in reference to the vertical ruler (11),to a height equivalent to the volume of liquid desired to be dichargedduring each cycle.

When the level in both recipients reaches the top filling level value(21) set by the level regulator (18), the controllable floating device(20) activates the shut-off valve (19), stopping the filling and thisway putting an end to the load phase comprised in the preparationsubcycle, to initiate the wait phase. The necessary condition for acorrect operation is that the trigger discharge device (44) remainsretained in closing position, and the filling level control conduit(43), is fixedly shut.

It must be remarked that the regulated filling level (21) reached by theliquid should be constructively established, as is illustrated in FIG.3, in an intermediate value among the threshold to basic spontaneousdischarge UDB (40) and the global spontaneous discharge threshold UDG(41) settled down by the addition of two phenomenons, that is:

1) the formation of a column of water in the space left between the exittube (35) and the third inverted glass (34) of the elbow sector (30)with the collaboration of supplementary input threshold device (28); and

2) the presence of liquid in the space comprised between the bottom endof the exit tube (35) and the up glass (36) included in thesupplementary discharge threshold device (29), what forces the airdisplaced by the liquid looking for discharging, to overcome an overpressure threshold equivalent to the height reached by this liquid.

In consequence, the reached wait state is characterized by anindefinitely stable equilibrium, based on a condition of anunsurpassable (without further external actions) threshold of potentialenergy as pressurization of the air caught in the camera (31) belongingto the device (28).

While, the watering command assembly (4) has determined the just momentto execute the discharging part of the cycle, by processing data of thecultivation as for example soil humidity and temperature; ambientparameters as for example temperature, humidity and atmosphericpressure; and also acquiring the operation status of the wateringsystem; these data being manually set, programmed or provided by thesensors (88) and (59).

In order to make its calculus, the command assembly considers data thatis a characteristic of the cultivated species joint with desirableevolutionary parameters according to the time elapsed from the initialplanting date; these data being for example incorporated in the Expertapplication software that resides residing in the memory means (78),(79) and (80) of the electronic low power command module (70). Theelectronic circuit carries out the above calculation in few miliseconds,remaining almost all of time in a low consumption stand by condition.Only the real time clock circuit (75) remains active thanks to theindependent power source (76).

When the current time reaches the calculated value, the awakening of thenecessary circuits takes place in order to produce the execution of thedischarge. Once executed and after a new calculation, the command module(70) returns to the stand by state with minimum energy consumption.

Being very small, the electric energy required for this kind ofoperation is easily supplied along the watering cycle and surelyreserved duing several days or weeks by means of the photovoltaicconverter (97) and the electric accumulator (83).

Once reached the moment calculated for make the discharge or properlywatering phase, the interface output circuit (81) sends an unique andbrief (some tenths of milliseconds long) current pulse of appropriatepolarity, toward the actuators optionally configured as active; in thisexample limited to the discharge actuator subset (24) and specificallyto the trigger discharge device (44), positioning in an auto-retainedopen state, the pneumatic bistable electrovalve (45).

In this position, the pressurieed air that was formerly caught in thecamera (31) escapes.

So disappeared the support of the supplementary threshold (38) and—beingfilled with liquid the tube (35)—being nulled the supplementarythreshold of discharge UD (39), it becomes broken the previous stablebalance.

In fact, everything happens as if the threshold of spontaneous dischargehad decreased suddenly from its former value UDG (41) to the new valueUDB (40), lower than the current regulated filling level (21) of theliquid in the container and recipient. The result is a neat shot of thedischarge process through the discharge actuator subset (24) whichduring discharge, acts as a conventional siphon device.

However, it would operate defectively without the intervention offurther auxiliary mechanisms that are included in the Invention.

It is well known the fact that the normal operation of the conventionalsiphon device requires the complete purge of the air possibly caught inthe hydraulic circuit and particularly in the area of the elbow. Withoutthis proceeding, or if an air filtration takes place, the dischargewould be surely aborted.

This operating error is prevented by the hermetic closing of therecipient (14) by means of the superior cover (15), and specifically bythe action of the unidirectional expansion valve (55), only necessarywhen being used the option of external auxiliary tank as is the presentimplemented example of the Invention. Indeed, this valve allows thenormal evacuation of the displaced air as the loading of the recipient(14) and the deposit (2) takes place, but its entrance is not allowedwhen the discharge proceeds, assuring the complete transmission of thesuction taken place by the descending mass of liquid, until its completeemptying.

A similar phenomenon happens in the first moments of the discharge shot,when a sudden sign change of the pneumatic pressure into the wateringactuator takes place. Indeed; once produced the opening of the pneumaticbistable electrovalve (45), the air over pressure in the camera (31)descends toward the atmospheric value, but as the discharge process istriggered, in a few seconds this pressure continues descending reachinga negative value equivalent to the height of the liquid accumulated inthe deposit (2). If this electro-valve does not transition quickly tothe closing state, the entrance of air due to the mentioned phenomenonwould interrupt the discharge. Accordingly, the command module can beprogrammed to send a current pulse with closing polarity a brief delayafter the beginning of the discharge. This characteristic preserves thecontrol capacity over the duration of the discharge for the commandgroup, being been able to use this option to adjust by this procedurethe actual volume to discharge in the current cycle, without varying thevertical position of the watering actuador (3).

However, a more exact and general solution is obtained by means of theunidirectional pneumatic retention valve (46) comprised in the triggerdischarge device (44). Said valve (46) doesn't interfere with thetrigger phase in which the air circulates in the allowed sense, but itcuts the flow as soon as this is inverted, assuring the continuity ofthe discharge until its end. Although all control becomes lost duringthe discharge, the resultant benefit is positive, being gotten a verysure time margin to restore the closing of the electrovalve (45) withoutrisk of doing it prematurely. By allowing both possibilities, theInvention will be able to adapt its configuration to the most convenientcontrol strategy.

Beyond avoiding said inconvenient phenomenon of pneumatic depression inthe actuator, the present Invention extrac advantages, by using it toadd concentrated liquid agrochemicals, by means of a chemigation doser(57) of the vacuum actuated, through the vacuum conduit (56). Saidincorporation takes place under favourable conditions, i.e.:

1) Use of small volume of concentrated liquid;

2) The chemicals addition takes place only during the discharge,discarding processes of chemical degradation or formation of colonies ofmicroorganisms in still water;

3) The addition of the desired quantity of chemicals (i.e. liquidfertilizer), is progressively distributed along a plurality of wateringevents. The dosage is this way strictly proportional to the total volumeof water discharged during a relatively long period of time. This factallows the user to adapt ecologically the given dose, to the rhythm ofabsorption that is adequate to the system cultivation-soil.

4) Incorporation in the most turbulence point, assuring a homogeneousmixture; and

5) Precise dosage, because of being the vacuum law against time, onlyfinction of constant dimensional or stable operative parameters.

However, it is in the low hydraulic restriction presented to thedischarge and distribution of the irrigation liquid, where thefertigation is specially improved by the present Invention, throughdecreasing drastically the risk of obturations.

Once being initiated, the discharge phase proceeds typically at highflow due to the low hydraulic losses presented to the circulation by thehydro-pneumatic siphon device (25) and the conduits (12) and (27).

The discharge flow regulating valve (100) allows to reduce this flow incase that the conditions of the soil absorption or the necessities ofthe cultivated species advise to do it, so increasing the applicationperiod of time.

Through this valve, the liquid enters in the watering distributionnetwork (5), characterized by its low hydraulic restriction. The primaryand secondary branches (101) and (102) low pressure demanded, maygenerally be implemented with low internal ruggedness and wide sectionplastic pipe, with the consequent low friction losses. The wholehydraulic restriction concentrates, then, in the emission points.

The emitter holes (103) may have sufficiently wide diameters, forexample between 1,5 and 5 millimeters, as to eliminate the pluggingrisk, yet maintaining a restriction between 100 and 300 times biggerrespect to that of the branches where they are practiced.

It should be remarked that it is indeed accepted in the specializedliterature that with said emission holes dimensions, the obturation riskbecomes practically null.¹³

The feasibility to practice in the pipe this holes with repeatedly equaldimensions (or following a predetermined compensation law) isindustrially simple. So, it is reasonable to expect great similarity inthe emitting holes (103) over the whole distribution network, with theconsequent uniformity of the quantity of water fed to the plants,attained at a very low manufacturing cost.

This emitter holes (103) optionally can discharge through terminalemitting means (104) with generally greater hydraulic conductivity incomparison with that of said holes (103) (for example small microtubesegments) whose function is to drive the liquid toward the mostappropriate point as established by the case agronomic modality.

From the previous description, it arises clearly that the Invention isvery appropriate for its employment in fertigation, being discarded allformation, fixation or obstruction risk to the distribution network bynon-desired microorganism colonies.

Working as described, the Invention is able to usually operate inautonomous, repeated way for an indefinite lapse without necessity ofattention, assuring an appropriate feeding to the plants under watering.

But still in the emergency of a complete fail in the electronic lowpower command module or its power source, the controller is able tocontinue operating exclusively on base of hydraulic principles.

To allow it, three simple operations must be done:

1.—Leave the pneumatic bistable electrovalve (45) in a retained shutposition, or simply plug permanently the discharge control conduit (26);

2.—Remove the controllable floating device (20); and

3.—Adjust the input flow regulator (17) until achieving a small flowwater entrance, so that the duration of the watering cycle is determinedby the time necessary to this flow to fill the container until the levelof spontaneous discharge.

If the recipient (14) has enough height as to allow that its contentsurpasses the level of spontaneous discharge previously defined, theloading will proceed slowly until, reached said level, the dischargetakes place in an entirely similar form to the normal operation.

Similarly, successive cycles will be repeated indefinitely, with theunique difference that in this case the repetition rate is determined bysaid adjustment of the input water flow.

Variations Comprised in the Invention

The Invention includes a plurality of structural and operativevariations that exceed the preferred embodiment described above.

For example, it was already mentioned that a pneumatic depression takesplace in the camera (31) during the discharge and that it is necessaryto not allowing the entrance of air that would interrupt it, by means ofdirectional valves. However, this phenomenon may be positively employedin the Invention as a simple method to obtain a controlled interruptionof the discharge and in consequence a control over the volumedischarged, method that results alternative to that previouslydescribed. Indeed; if during the discharge process the watering command(4) produced the opening of the pneumatic electrovalve (45) (being inthis case disabled the retention valve (46)), it would cause an airentrance and consequently the immediate stop of the watering pulse. Plusstill, any means that during the discharge allowed the entrance of airto the camera (31), would have produce the same shut-off effect.

So, a device able to determine repeatedly the magnitude of thedischarged volume could consist on a simple vertical pipe, flexiblycommunicated through its top end with said camera (31) and being itsbottom end submerged down to certain depth in the water contained in thedeposit. In such a way, the interruption will proceed as soon as thedescending level of liquid frees the entrance of air through said bottomend of the mentioned pipe.

Further; an important and simplified variation of embodiment of thewatering actuator assembly could consist in:

A.—a filling controller subset physically separated from the dischargeactuator subset and fixedly positioned near the top of the deposit as asimple floating shut-off filling level control device;

B.—a discharge actuator subset also located in a fixed position inreference to said fix filling level; and

C.—an adjustable discharge shut-off switch by means of the positionablepipe before noted.

In this implementation the operation is entirely similar to thepreviously described, except in that the filling level is fixed andcoincident with the maximum capacity of the deposit, while the dischargeproceeds until a minimum or interruption level determined by the bottomend of the mentioned vertical pipe.

Other embodiment variations—among the many possible ones—are enumeratednext to the following titles:

WATERING SYSTEM

Comprising one or more local subsystems, with or without link with aremote control central station.

LOCAL SUBSYSTEM DEPOSIT

It may consist simply in the recipient comprised in the dischargeactuator subset, or extend its capacity by means of an external deposit.

Said external deposit can be simple or built with a plurality ofcommunicated recipients.

WATERING ACTUATOR

The automatic cycle operation may be based on a controlled filling inputflow together with an spontaneous discharge mechanism, withoutemployment of any electronic command circuit. This way, the cyclingirrigation frequency may be regulated by the magnitude of entrance flow,by filling level or by discharge triggered by air relief as previouslyexplained.

The cyclic discharged volume may be controlled by pneumatic shut-off(minimum level control) or by vertical positioning of the actuator(maximum or filling level control); this vertical positioning beingmanual, automatic and/or by means of a closed-loop servo mechanism.

Depression activated ferti-irrigation dosage may be included as astandard basic embodiment.

WATERING COMMAND

Control of the total quantity of water fed daily to the cultivationthrough adjustments of volume discharged by cycle or of the frequency ofthe cycles.

Different configuration of the control variables: evening light sensors,clock calendar, actual demand of the cultivation, environmentalconditions, watering history, expert system, productive plan.

Local and/or remote optional modes of control

Alarm and/or compensation for lack of entrance of water.

Autonomous feeding from solar energy conversion along with battery backup; or from dry batteries; or from the electric net.

DISTRIBUTION NETWORK

Emission pipes comprising simple holes, optionally added withmicrotubes; or any kind of porous conduits or tapes; or other emittermeans presenting low hydraulic restriction.

Feeding individual plants located in soil, set in containers orinclusive through filling furrows.

From what was explained above, it can be seen that the present Inventionallows to use, by means of minor variations, a unique basicimplementation of watering controller in applications requiringdifferent performance levels, but in all the cases fulfilling theproposed finalities.

In a same way it also arises clearly that the present Inventioncomprises a sole and unique main object, nevertheless its versatilityand the wide spectrum of embodiments with which it can be industriallymanufactured.

Said unique structural principles that constitute the main object of thepresent Invention are remarked in the following paragraph.

The main object of the Invention

The hierarchical array of main structural principles that characterizesand provides novelty to the Invention is:

A SELF-SUSTAINED ECOLOGICAL IRRIGATION SYSTEM integrated by one or morelocal subsystems, each local subsystem comprising:

a) a water container having enough capacity to contain the total volumeof water to be discharged during one watering cycle, hydraulicallyjoined to

b) a positionable watering actuator assembly that includes:

b.1. a filling controller subset integrated by:

b.1.1. an input flow regulator; and

b.1.2. a controlled level regulator;

b.1.3. a limited capacity hermetic recipient or body;

b.1.4. an expansion valve;

b.1.5. a capacity expansion shuttable connector; and

b.1.6. a vacuum conduit connection to a chemigation doser;

b.2. a discharge actuator subset comprising:

b.2.1. a hydro-pneumatic siphon device;

b.2.2. a supplementary input threshold devise; and

b.2.3. a supplementary discharge thershold device;

b.3. a trigger discharge device; and

b.4. a vertical displacement servomechanism;

c) a watering command assembly, comprising:

c.1. a low power command module;

c.2. a plurality of feedback sensors;

c.3. a plurality of electrical pulsed control output means;

d) a low hydraulic restriction watering distribution network,comprising:

d.1. a plurality of central or feeding branches, feeding

d.2. a plurality of emitting or peripheral conduits presenting

d.3. a plurality of local emitting orifices; each one watering through

d.4. terminal located emitting means.

Being so defined the mentioned main principles of the Invention it mustbe stressed that, besides the described options, the industrializationand/or marketing processes may give place to minor additionalconstructive modifications that will not appart from the protectionsphere clearly stated by the following array of claims.

Bibliographic References

¹ Pizarro, Femando “Riegos localizados de alta frecuencia”; Madrid,España.

² Nijensohn, León; “El riego por goteo como método de lavado de suelossalinos”; Seminario Internacional sobre Riego por Goteo; IICA (OEA);Mendoza, Argentina, abril de 1975.

³ Pizarro Cabello, F.; Op. cit.; p.p. 150

⁴ Rodrigo López, Jesús et al. “Riego Localizado”. Mundi-Prensa, Madrid,1992; p.p. 171

⁵ Pizarro Cabello, F.; Op. cit.; p.p. 161.

⁶ Israelsen, Orson W.; “Principios y aplicaciones del riego”, Ed.Reverté, 1985.

⁷Sagi, G. et al; “Clogging of Drip Irrigafion Systems by ColonialProtozoa and Sulfur Bacteria”; p.p. 244, Proc. of 5th. MicroirrigationCongress, April 1995, Orlando, Fla., U.S.A.; American Society of AgricuEngineers.

⁸ Dalvi, V. B. et al; “Growers' Experiences and On-Farn MicroirrigationEfficiencies”; p.p. 775; Proc. cit.

9 Pizarro Cabello, F., Op. cit., p.p. 373.

¹⁰ Pizarro Cabello, F.; Op. cit.; p.p. 323.

¹¹ Spencer Lloyd; U.S.Pat. No. 3,797,741; 1974; Abstract; U.S.P.T.O.

¹² Desrues, E; Chaumontet, B. & Lemery, J. P.; French Patent FR2.665.051; 1992; INPI

¹³ Edling, R. J. & Gaspard, M. J.; “Solar Power Supply System Design forIrrigation Control at Remote Sites”; p.p. 223; Proc. cit.

¹⁴ Rodrigo Lbpez, J. et al; Op. cit.; p.p. 32.

What is claimed is:
 1. A self-sustained ecological irrigation system capable to produce repeated cycles of uniform located irrigation into a cultivated area, of the type comprising a plurality of local subsystems (1) assisting generally different and physically apart cultivated areas; said local subsystems being linked with a central station (6) to receive remote control; said central station comprising codifying, adressing and transmitter circuits capable to send remote control orders with sufficient energy to be received by the adressed local subsystems (1); characterized in that each one of said local subsystems (1) comprises a liquid container (2) with enough capacity to contain at least the total water volume to be irrigated during one cycle, being the container (2) hydraulically joined from its bottom zone with a positionable watering actuator assembly (3); said positionable watering actuator assembly (3) being by one side electrically connected to receive control signals, with a watering command assembly (4) capable to determine the characteristics of the watering cycle and command their execution; and being by the other side hydraulically joined to feed a low friction losses watering distribution network (5), capable to subdivide uniformly the discharged volume of liquid and emitting it in located points into the cultivation area; said positionable watering actuator assembly (3) comprising a recipient hermetically closed by a top cover; said recipient including a first filling controller subset (16) driven by the relief of pressurized air, able to controllably limit the irrigation water entrance to the recipient from an external source; a second discharge actuator subset (24) providing at least one dimensionally defined threshold level of controlled triggerable discharge driven by the relief of pressurized air; being said discharge actuator subset (24) able to transit abruptly fiom a closing state to another of full open passage with low friction losses, if being surpassed said threshold by the current level of the liquid; both first and second subsets being fixedly height positioned one relative to the other, in funtion of the desired relationship among the designed filling and discharge threshold levels already mentioned; said positionable watering actuator assembly also comprising externally fixed to the top cover of said recipient, at least one trigger discharge device (44) able to relieved pressurized air, connected to control at least one of the above mentioned subsets; said trigger discharge device (44) presenting meanss of electrical connection to receive from said watering command assembly (4), impulsive activating signals for change of state; said positionable watering actuator assembly (3), at last comprising a mechanism for vertical positioning of itself in reference to the desired level of filling of the mentioned container (2).
 2. A self-sustained ecological irrigation system as claimed in 1, characterized in that the mentioned filling controller subset (16) comprises a first device (17) of input flow regulator; a second device (18) of controlled filling level regulator comprising a shut-off valve activated by a controllable floating device; said controllable floating device including at least one bottom opened air trapping camera, being said camera top provided with a pneumatic air reliefing connection; said pneumatic air reliefing connection emerging from the recipient through its top cover, being able to be optionally sealed or connected with the trigger discharge device (44) former mentioned to control the filling level of the container (2); the mentioned recipient also presenting at its bottom zone a capacity expansion shuttable connector, able to fix a flexible conduit of adequate section to conduct with low hiydraulical losses the discharge flow coming from the mentioned container (2); being additionally fixed in said top cover an unidirectional pneumatic valve (46) optionally set in a permanent shut state, capable to retain a partial pneumatic depression produced during the discharge process inside the recipient; further presenting fixed in said top cover the emergent connection of at least one aspiration conduit able to admit the incorporation of liquid agrochemical additives, being the opposite end of said aspiration conduit connected with depression activated doser means.
 3. A self-sustained ecological irrigation system as claimed in 2, characterized in that said device (17) of input flow regulator comprises a liquid doser mean electrically adjustable by electric signals, this signals being provided by the watering command assembly (4) previously mentioned.
 4. A self-sustained ecological irrigation system as claimed in 1, characterized in that the mentioned discharge actuator subset (24) comprises a hydro-pneumatic siphon device (25) comprising three hydraulically consecutive parts, being: a first ascending part called input sector, a second intermediate part (30) called elbow sector, and a third descending part called discharge sector; presenting connected in series wit said ascending part a device (28) provider of a supplementary input threshold (UT); being said elbow sector (30) a hydraulic device able to invert the ascending sense of the liquid circulation through a progressive section transition providing laminar flow and precise definition of an irreversible triggering transition level to discharge, called threshold to basic spontaneous discharge (UDB); being said third descending part connected with a hydraulic device (29) provider of a supplementary discharge threshold (UD); the whole hydropneumatic siphon device (25) presenting a precisely defined global spontaneous discharge threshold level (UDG), equivalent to the sum of said threshold to basic spontaneous discharge, added with both two mentioned supplementary thresholds (UDG=UDB+UT+UD); said hydropneumatic siphon device (25) comprising at least one pressurized air camera (31) sustaining without discharge the pressure generated by a liquid level into the recipient of a value between the former mentioned thresholds of basic (UDB) and global (UDG) spontaneous discharge levels; said pressurized air camera (31) presenting in its top zone a pneumatic control connection, able to allow the evacuation of the trapped air to trigger the hydraulic discharge process through said siphon device (25) and discharge conduit (35).
 5. A self-sustained ecological irrigation system as claimed in 1, characterized in that said trigger discharge device (44) by relief of pressurized air comprises at least a pneumatic bistable electro-valve (45), able to evacuate said trapped pressurized air while staying at a self-retained open state, from said filling controller and discharge actuator subsets in order to execute its control; said electro-valve (45) comprising a pneumatic circuit including an unidirectional pneumatic valve optionally disabled; and at least a magnetic loop circuit energized by a high inductance solenoid winding able to be electrically activated by a suitable current pulse provided by the watering command assembly (4) already mentioned; said magnetic loop circuit closing partially through a mobile magnetic nucleus as it moves limitedly when forced by a magnetic field; said magnetic field being established by the circulation of a brief electric current pulse through the above mentioned solenoid winding; being included in said magnetic loop circuit at least a retention mean of the mentioned mobile nucleus in its open position, still in absence of the activating current; said mobile magnetic nucleus including at least a resilient seal mean able to controlably close the passage of pressurized air through the former mentioned pneumatic circuit.
 6. A self-sustained ecological irrigation system as claimed in 1, characterized in that the already mentioned waterig command assembly (4) comprises an electronic command module (70) with low electrical power consumption, capable to process informaion to determine the parameters of the watering cycle and at the proper time emit activating low energy control signals to execute it; said electronic command module (70) comprising a water tight sealed cabinet, housing at least a first circuit for attending local controls; a second circuit decoder of remote control signals; a third circuit conditioner of sensors and a fourth real time clock circuit backed by an independent power source; the four circuits mentioned being connected to provide information signals to a fifth circuit of logical processor; this circuit of logical processor being bidirectionally connected with a sixth circuit of permanent memory container of an operative program; said four circuits being also connected with a seventh circuit of recitable memory, which in turn includes an eighth circuit of non-volatile removable memory chip; said circuit of logical processor being connected with a ninth interface power output circuit to exit impulsive watering control signals; said interface including a servo-mechanism control circuit capable to adjustably command the vertical positioning of the positionable watering actuator assembly previously mentioned; the above circuits being implemented by means of minimum power consumption electronic technology and energized by a tenth power circuit connected to receive electric power from an external autonomous power source (76) requiring low maintenance, comprising a mean of photovoltaic converter (97) dimensioned with enough capacity to assure the autonomous operation of the mentioned watering command assembly (94) yet in the most unfavorable case of solar condition; said tenth power circuit being also connected to a mean of rechargeable electric accumulator (83), dimensioned to guarantee the autonomous operation of the watering command assembly during an sufficient long period of time in the event of temporary reduction of energy provision by said external autonomous power source (76); presenting the sealed cabinet before noted a plurality of connection means with external circuits; said external circuits comprising at least means of local control, a remote control receiving circuit, and a plurality of sensor means capable to acquire feedback information originated at the cultivation, at the environment or at the watering process itself; being output control signal connection means of said low power command module also connected to the positionable watering actuator assembly (3) former mentioned.
 7. A self-sustained ecological irrigation system as claimed in 1, characterized in that said watering distribution network (5) comprises in first place a discharge flow regulating valve (100), continued for at least one primary feeding branch (101), which in turn is connected with a plurality of derived secondary peripheral emiting branches (102); said secondary feeding branches having practiced a plurality of emitter holes (103) of a significative bigger size than the biggest particles present in the irrigation water; being said holes still enough sized to allow the quick evacuation toward the cultivation of the located portion of the discharged volume; being the hydraulic restriction exercised by said emitter holes (103) significantly larger than that of the the above mentioned secondary peripheral emitting branches; having inserted each one of said holes, terminal watering emitter means (104) presenting generally smaller hydraulic restriction than that of the mentioned emitter holes. 